Sodium Lauryl Sulfate, also sodium Laureth Sulfate is found in lots of cosmetics. You will find it in toothpastes, shampoos, body washes, hand washes amongst other things. This compound has been linked by some to cancer (see further below), eye disorders, rashes, hair loss, dandruff and allergies.

Its actually used as an engine degreaser and floor de-waxer (used in places like mechanics' garages).

Just download the standard Material Safety Data Sheet for sodium lauryl sulfate which establishes that at the least it is in an irritant and is toxic.

Sodium lauryl sulphate (SLS) is an anionic surfactant (detergent) which is included as a foaming agent (to clean and make bubbles) in a huge variety of commonly used products. These include shampoos, soaps, face and body washes, toothpaste, washing up & laundry detergents and also industrial cleansing chemicals such as engine degreasers. There are many derivatives of SLS that can be found in commercial preparations, including sodium laureth sulphate, sodium laureth-3 sulphate, and DEA or teasodium lauryl sulphate. Although these derivatives may vary slightly in mildness, the general action and effects are essentially similar.

Growing Concern

Recently, there has been growing concern about the widespread use of these detergents and their safety has been called into question. In this report, we will review the scientific literature available and show why it may be wise to attempt to minimise your exposure to this family of foaming agents.

A major concern about SLS is the effect that it has when used in combination with other ingredients commonly found in personal care products. SLS has the potential to react with other ingredients (e.g. 2-bromo-2-nitropropane-1,3-diol, DEA, MEA, TEA) to form nitrosating agents, which in turn can form nitrosamines, which are known to be carcinogenic.

Similar names, different effects

There are several other surfactants with similar names to SLS - in particular ammonium lauryl sulphate and ammonium laureth sulphate. Although these sound very similar their molecular structure is significantly different and they do not have the same potential to irritate the skin. Also, because their molecules are larger than those of SLS, they are not able to pass through the skin and therefore cannot be absorbed into the body in the same way. Because of these differences, ammonium lauryl and laureth sulphates are considered to be milder and safer alternatives to SLS.

SLS can penetrate the cornea of the eye (even if absorbed through the skin), accumulate readily and is released slowly. These effects are greater in younger individuals (7). A single drop of SLS can remain in the body for 5 days, so if you wash a childs hair more than once a week with a SLS containing shampoo, there will be constant levels of SLS present.